The invention is based on a control device for the coolant flow in a cooling circuit of an internal combustion engine having a housing with an inlet opening, an outlet opening, a channel extending from the inlet opening to the outlet opening and a movable control element for varying the flow-through cross section of the channel.
A control device of this type is known from DE 10 2006 038 213 A1 and comprises a seal arrangement that consists of a sliding ring of PTFE and a sealing ring of elastomeric material. The known control device comprises a control element, the sealing surface of which is spherical. On its side facing the control element, the sliding ring is shaped such that it is adapted to the spherical surface of the control element. The sealing surface of the sliding ring is relatively large and extends from the front side of the sliding ring up to its rear side that faces the sealing ring. The sealing ring not only has sealing properties, but also resilient properties, wherein its resilient force should only increase slightly when a deformation force acts upon the sealing element in order to allow a sound tolerance compensation. The sealing ring rests against the housing at multiple locations.
EP 2 295 757 A1 discloses a non-generic control device, in which a sealing surface of a seal arrangement resting against a control element and a sealing surface of the seal arrangement resting against a housing are realized on the same elastomeric component. A section of the seal arrangement, which comprises the sealing surface resting against the housing, is designed in the form of a sealing lip. In the closed position of the control element, a passage of the seal arrangement is connected to a downstream channel section. The inner and outer circumference of the sealing lip increase in the direction toward the housing. The seal arrangement is radially pressed against the wall of the control element from outside under the influence of the pressure of the coolant supplied through an inlet opening. Since the sealing surface of the seal arrangement resting against the control element consists of an elastomer, a high torque is required for moving the control element, particularly at a relatively high pressure differential between the inlet and the outlet. A drive unit for the control element therefore has to be dimensioned relatively strong.